It is known to support flexible hoses which define a tubular, undulating or bellows-like envelope with axially extending cables which are held against the hose by spacer elements fitted into the valleys of the undulation of the hose or tube. Usually, two cables are located outside of the tube, essentially diametrically positioned with respect to each other. The spacers determine the relative position to the hose envelope. The spacers are distributed, in predetermined distances, over the length of the hose. They are formed with holes through which the cables can pass. Desirably, the cables are located in a neutral plane.
The hose structure to which the present invention relates, including the undulations, may be termed generally ring-shaped. The rings need not be circular, since the cross section of the hose may be other than circular, for example oval, or some other non-circular cross section. Such hoses, which are also referred to as bellows elements or bellows hoses, are usually made of metal. In dependence on the intended use, other materials may be employed, such as plastics. The hoses frequently are used to form a flexible connection between two relatively movable elements, and carry media which are to be coupled to the two elements. The medium retained within the flexible hose may be pressurized, with the result that the internal pressurized medium has a tendency to increase the length of the corrugated tube. To prevent such increase in length, the cables which are placed outside of the tube maintain the respective longitudinal spacing of connector ends coupled to the respective elements and, additionally, support the hose against sharp bends, breakage, or lateral escape. The hoses, additionally, may be used to retain or provide protective covering for other media than fluids, for example electrical cables or the like, which are to be connected, for example, between a fixed terminal or junction element and a movable element.
The structure described in the referenced application Ser. No. 06/897,523, Gronert et al, provides for effective support of the hose, so that it will not be subject to friction stresses, and hence wear and tear at rubbing or engaging surfaces between, for example, the tube structures and the cables, or other parts or components. This is particularly important if the hose structure is subjected to changing bending stresses. Frictional engagement of the cables or other parts with the hose structure decrease its lifetime and wearing or rubbing surfaces particularly impair the integrity of the hose structure. The frictional engagement of the cables with the hose itself can be reduced by locating the cables in the neutral bending plane, if this bending plane is invarying, of the hose. No relative movement with respect to the hose, neither in longitudinal nor in circumferential direction, will then result. The spacers then have the function to maintain the cables in the determined relative position to the hose structure itself. Usually, the cables are made in the form of ring disks, fitted into the valleys defined by the undulation of the hose. The disks or spacers are formed with holes through which the cables can pass, thereby positioning the cables with respect to the hose.
The system works well, but it has been found, in assembly, that problems arise with threading the cables through the holes of the spacer disks. This becomes particularly important when one considers that the ends of the cables could be connected to cable end terminal parts only after they have been threaded through all the ring disks which are to be placed around the hose itself. Threading cables which are made of fibers or rope structures of wire is difficult and the danger of unwinding of spiral wires or separation of individual strands of ropes or wire ropes causes difficulty in the manufacture and, further, in the connection between the ends of the ropes and terminal parts themselves. This is particularly important if the lengths of the ropes are precut, so that the terminal parts of the ropes must be held tightly together to permit threading through the spacer holes. The threading operation is difficult and time-consuming and pure manual work. Pre-assembling such reinforced or supported hose structures in automated production is not possible.